Integrated circuits (ICs) are commonly employed in various electrical/electronic devices. The ICs are often subject to constraint of temperature in order to maintain proper operation. In other words, heat generated by the ICs must be timely removed in order to maintain proper operation temperature of the ICs. A heat dissipation device is often employed to remove heat generated by the ICs. This is of vital importance for some ICs, such as a central processing unit (CPU) of a computer system, for the CPU is the core of operation of the computer system. Malfunctioning or improper operation of the CPU due to undesired high temperature usually results in system failure of the computer. A conventional heat dissipation device for the computer CPU comprises a thermally conductive board mounted on the CPU and a plurality of space fins extending from the board. Airflow induced by a cooling fan passes through channels defined between adjacent fins effectively remove heat from the fins by convection, as well as radiation.
With the increase of operation speed (or system clock) of the computer, heat generated by the CPU is remarkably increased. However, for such high-speed computers, heat removed from the CPU by the finned heat dissipation device is not sufficient to maintain the operation temperature of the CPU. This is especially true for computers having small physical size, such as a notebook computer, which has an impact arrangement of electronic parts, making it extremely difficult to install a large-sized heat dissipation device having large capacity of heat removal.
In addition to the finned structure and the fan that causes airflow through the finned structure, a heat pipe is commonly employed in the notebook computer to enhance heat removal. Opposite ends of the heat pipe are in physical engagement with the thermally conductive board that is positioned on and in contact with the CPU and the finned structure through which the airflow passes for facilitating transfer of heat from the CPU to the finned structure from which the heat is carried away by the airflow.
The heat pipe facilitates transferring heat from the board positioned on the CPU to the finned structure to allow heat to be removed by airflow. However, due to the significant different in size between the heat pipe and the board, heat that is transferred from the board by the heat pipe is constrained to a local area around the contact point between the heat pipe and the board. Most of heat is still accumulated in the board at locations other than the contact point between the heat pipe and the board. This limits the effectiveness of transferring heat from the board by the heat pipe.
Modifying the overall configuration and arrangement of the heat dissipation device or the contact point between the heat pipe and the board, may be helpful in overcoming the problem. However, due the physical limitation of the compact space inside the notebook computer, and also due to the existing arrangement of the electronic/mechanical components inside the notebook computer, such a modification is, in fact, very difficult and impractical, if not impossible.
Thus, the present invention is aimed to overcome the limitation of heat transfer in the conventional designs in order to enhance heat transfer in a heat dissipation device without significant modification of the existing arrangement inside an electronic device that employs the heat dissipation device to maintain proper operation temperature.